LP2956 Datasheet, PDF (5/16 Pages) National Semiconductor (TI) – Dual Micropower Low-Dropout Voltage Regulators

Electrical Characteristics (Continued)
Limits in standard typeface are for T_J = 25˚C, and limits in boldface type apply over the full operating temperature range. Lim-
its are guaranteed by production testing or correlation techniques using standard Statistical Quality Control (SQC) methods.
Unless otherwise specified: V_IN = 6V, C_L = 2.2 µF (Main Output) and 10 µF (Auxiliary Output), Feedback pin is tied to 5V Tap
pin, C_IN = 1 µF, V_SD = 0V, Main Output pin is tied to Output Sense pin, Auxiliary Output is programmed for 5V. The main
regulator output has a 1 mA load, the auxiliary regulator output has a 100 µA load.
Symbol
Parameter
Conditions
Typical LP2956AI
LP2956I
Units
Min Max Min Max
AUXILIARY COMPARATOR
HYST
I_OH
V_OL
I_B
Hysteresis
Output “HIGH” Leakage
Output “LOW” Voltage
Input Bias Current
V_OH = 30V
V_IN (COMP) = 1.3V
V_IN (COMP) = 1.1V
I_O(COMP) = 400 µA
0 ≤ V_IN (COMP) ≤ 5V
6
mV
0.01
1
1
µA
2
2
150
250
250
mV
400
400
10
−30 30 −30 30
nA
−50 50 −50 50
GROUND PIN CURRENT
I_GND
Ground Pin Current
I_L (Main Out) = 1 mA
170
(Note 15)
I_L (Aux. Out) = 0.1 mA
I_L (Main Out) = 50 mA
1.1
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 100 mA
3
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 250 mA
16
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 1 mA
3
I_L (Aux. Out) = 50 mA
I_L (Main Out) = 1 mA
6
I_L (Aux. Out) = 75 mA
I_GND
Ground Pin Current
V_IN = 4.5V
at Dropout (Note 15)
I_L (Main Out) = 0.1 mA
270
I_L (Aux. Out) = 0.1 mA
I_GND
Ground Pin Current
No Load on Either Output
120
at Shutdown (Note 15)
I_{(SD IN}) ≥ 1 µA
250
250
µA
280
280
2
2
2.5
2.5
6
6
8
8
28
28
mA
33
33
6
6
8
8
8
8
10
10
325
325
350
350
µA
180
180
200
200
Note 1: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the de-
vice outside of its rated operating conditions.
Note 2: The maximum allowable power dissipation is a function of the maximum junction temperature, T _J(max), the junction-to-ambient thermal resistance, θ _J-A,
and the ambient temperature, T_A. The maximum allowable power dissipation at any ambient temperature is calculated using: P(max) =
.
Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. See Application Hints for
additional information on heat sinking and thermal resistance.
Note 3: When used in dual-supply systems where the regulator load is returned to a negative supply, the output voltage must be diode-clamped to ground.
Note 4: May exceed the input supply voltage.
Note 5: Output or reference voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 6: Load regulation is measured at constant junction temperature using low duty cycle pulse testing. Two separate tests are performed, one for the range of 100
µA to 1 mA and one for the 1 mA to 250 mA range. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential. At
very low values of programmed output voltage, the input voltage minimum of 2V (2.3V over temperature) must be observed.
Note 8: Thermal regulation is the change in output voltage at a time T after a change in power dissipation, excluding load or line regulation effects. Specifications
are for a 200 mA load pulse at V_IN = 20V (3W pulse) for T = 10 ms on the Main regulator output. For the Auxiliary regulator output, specifications are for a 66 mA
load pulse at V_IN = 20V (1W pulse) for T = 10 ms.
Note 9: Connect a 0.1 µF capacitor from the output to the feedback pin.
Note 10: Load regulation is measured at constant junction temperature using low duty cycle pulse testing. Two separate tests are performed, one for the range of
100 µA to 1 mA and one for the 1 mA to 75 mA range. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 11: Dropout dectection comparator thresholds are expressed as changes in a 5V output. To express the threshold voltages in terms of a differential at the
Feedback terminal, divide by the error amplifier gain = V_OUT/V _REF.
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